Incorrect spelling, explanation: quizes is not the right spelling, because it ignores an important participle. As you can notice, this version only contains one -z letter. The right version should be written down with two -z letters. Why? If we want to create a plural form of the noun quiz, we need to add -es (instead of -s) to it – the -z letter can’t be followed by -s. The -e in quizzes has a short vowel sound and consonants in words with short vowel sounds are usually doubled. This is the explanation why this noun should be spelled quizzes, not quizes.

Correct spelling, explanation: if you’re wondering why there’s a double consonant in that word, we’re coming to help. Quizzes is the plural form of the noun quiz, which is commonly used in English. It consists of three parts: quiz + z + es. Quiz is the word-formation basis, -z is doubled, and -es is a plural suffix, as well as just -s. In this case, we have to add -es to the root, because it ends with -z. The -e letter has a short vowel sound. The crucial rule is: consonants in words with short vowel sounds are doubled very often. Therefore, the only correct spelling is quizzes, not quizes.

Definition of quizzes:
noun, plural of quiz, a game or competition in which you answer questions
There are many quizzes in my school. I don’t mind them though.
Historical quizzes are the worst. I hate them!

Collocations with quizzes:
Some most commonly used collocations include: online quizzes, take quizzes, and quizzes on [something].
I really hope that our mid-term exams will be in the form of online quizzes.
I love to take quizzes about my favorite TV shows.
Our quizzes on algebra will be really difficult.